0(1) element: null
1(2) element: PyImportStatement
2(3) WRITE ACCESS: sys
3(4) element: PyTryExceptStatement
4(5,15,22,25) element: PyTryPart
5(6,15,22,25) element: PyAssignmentStatement
6(7,15,22,25) READ ACCESS: open
7(8,15,22,25) WRITE ACCESS: f
8(9,15,22,25) element: PyAssignmentStatement
9(10,15,22,25) READ ACCESS: f
10(11,15,22,25) WRITE ACCESS: s
11(12,15,22,25) element: PyAssignmentStatement
12(13,15,22,25) READ ACCESS: int
13(14,15,22,25) READ ACCESS: s
14(15,22,25,30) WRITE ACCESS: i
15(16) element: PyExceptPart
16(17) READ ACCESS: IOError
17(18) WRITE ACCESS: errno
18(19) WRITE ACCESS: strerror
19(20) element: PyPrintStatement
20(21) READ ACCESS: errno
21(30) READ ACCESS: strerror
22(23) element: PyExceptPart
23(24) READ ACCESS: ValueError
24(30) element: PyPrintStatement
25(26) element: PyExceptPart
26(27) element: PyPrintStatement
27(28) element: PySubscriptionExpression
28(29) READ ACCESS: sys
29(30) element: PyRaiseStatement
30() element: null